Excavator



March 4, 1969 QsMANo BELTRAMI 3,430,790

ExcAvAToR l Filed March e, 1967 I sheet of 4 INVENTOR. os mimo BE www Marh4,1safi9l QSMANQ BELTRAMI 3,430,190`

ExcAvA'roR Filed March e, 1967 l H sheet 2 of 4 March 4 1969 Filed March 6. 1967 OSMANO BELTRAMI EXCAVATOR Sheet 3 ofei.

INVENTOR. OS m me fBEL wf' March 4, 1969 osMANov BELTRAMI 3,430,790

y EXCAVATOR.

Filed March e, 1967 sheet 4 ef e INVENTOR GS nmnB raamt United States Patent 3,430,790 EXCAVATOR @smano Beltrami, 220 Via Faentina, Ravenna, Italy Filed Mar. 6, 1967, Ser. No. 620,897 Claims priority, application Italy, Apr. 16, 1966,

Us. el. 214-138 s claims im. el. non 3/50; neng 17/00 ABSTRACT F THE DISCLOSURE Background of the invention This invention relates to an improved excavator, of the self-propelled type, mounted on Creeper tracks, wheels or the like, and comprising a boom by which a bucket is supported. Such excavators, which lare utilized under widely varying conditions and for the most different purposes-in general for all earthworks and in particular tor digging foundations, trenches and the likeusually 'consist of a stationary frame connected 'with the Creeper tracks or wheels land carrying a turntable that can be rotated on an axis perpendicular to the ground surface, and whereon the boom is itted, along with all required control devices, inclusive of the operators cab.

The already known excavators of the above described type, while allowing to have accurately vertical cuttings to be dug away, Iwhen they rest on a horizontal soil surface, are not able to give the same results in the by far more common practical cases of working on more or less slanting slopes, according to the condition of ground, as when working in the hills, or when digging chan-nels or trenches having banks at dierent levels. On the other hand, `and again for the same reasons, it will not be possible to dig trenches or the like with inclined side Walls, by an excavator resting on a horizontal plane, or at any rate on a plane not perpendicular to the side walls of a trench to be dug, since the bucket teeth, and the related bucket wall, are necessarily kept always parallel to the ground surface whereon the excavator rests.

Attempts have been made to remove, at least partly, such drawbacks, 'by having the turntable swivelingly tted on an axis, which extends longitudinally to the excavator frame, provision being made for controlling such swiveling motion by means of two vertically itted lhydraulic jacks, located on either sides of said axis, in order that the boom can be inclined at least in one direction, to bring it in a vertical position, when the excavator is working on slopes, or conversely to have t-he 'boom inclined, in order to meet given operating requirements. However, such solution, while really bringing some improvements in the Vattained practical results, is always necessarily restricted in its range of application and, at any rate, recourse can be made to it in given, particular cases only.

Another heavy restriction suffered by the heretofore commercially available excavators consists in that the /working range of the boom is rather limited in either vertical directions; a wider Working range can be obtained only by reverting to longer, and thus heavier booms, which results in a proportioned increase int-he overall sizes of excavator, and obviously also in the costs thereof; moreover, difficulties are encountered either when the lee boom is to be folded onto the machine, to convey the same on roads, and to dig shallow trenches close to the excavator.

Attempts have been made to remove the latter drawbacks .fby making the pivot point of the lifting cylinder adjustable, thereby allowing to change the emplacement thereof in respect of the turntable, or of the boom', according to the operational requirements, thus obtaining some improvements from the viewpoints of digging depth and of discharge height, though the effects of such expedients are again limited by the boom length on one side, and by the relatively small adjustments of said pivot point on the other side.

Finally, a thind, heavy drawback of conventional excavators can be traced back to the fact that the tread, i.e., the transverse distance between the longitudinal axes of their tracks or Wheels, is usually invariable, which results on one side-above all lfor digging trenches or the likein the necessity of reverting to different machines, according to the trench width, with consequent high operating costs, while on the other side, owing to normally great width of said tread, considerable diiculties are encountered in conveying said excavators across relatively large distances, since the crosswise sizes of excavators are in the most of cases too great, While as alternative, time-consuming and expensive dismantling operations would be required.

Summary of the invention This invention provides an excavator boom which can be inclined in any direction, in order to carry out digging operations even when the machine is resting on slopes, and allowing also to have the width of boom motions adjusted or modified, thereby increasing the attainable A depth or height, while permitting changes in the tread too, in order to facilitate the transport of machine on one side, land particular digging operations on the other side; the latter feature allows also to set the machine at work on parallel stepped slopes, at least within limits, as well as to work with the excavator frame resting on the ground, in order to prevent the shocks and jerks to which it is usually submitted when the machine is operating, from being transmitted to tracks or wheels, that are as a rule not very capable to stand up under the hardest usage.

Thus, the invention concerns an excavator with a boom carrying a bucket, and mounted on tracks, wheels or the like, and comprising means designed to allow and to control the swiveling motions of said boom in respect of the ground surface, through an inclination of the elements by which the boom is supported, in respect of the vertical axis on which the boom is usually rotated, being the possibility given to cause such inclination in any direction across an arc of 360 degrees around the same axis. In addition, means are preferably provided in order to change the tread width of tracks or wheels, and to allow same to rest on diferent levels at either tread sides, as well as means for shifting the pivot pins of the boom or ofthe cylinder(s) for lifting it, in order to increase the operating range of said boom.

According to the invention, the above stated means designed to allow and to control the inclination of the boom relative to the ground surface, consist of at least one ball-joint linkage, fitted between the boom supporting turntable and the stationary frame of the excavator, said ball-joint linkage being made up by at least two components, respectively connected with the turntable, and with the stationary frame of the excavator, and such components being formed with mating, reciprocally movable surfaces, shaped as spheric elements, and preferably as elements obtained from the central portion of a sphere, and delined by two section planes parallel with each other and to a sphere equatorial plane, and takenon either sides thereof.

The above-stated means for changing the tread of tracks or wheels, and for allowing the tracks or wheels to rest on stepped planes, advantageously consist of one, or more connecting rods, that are pivotally connected respectively with the tracks or wheels, and with the related sides of the frame, suitable means being provided for causing and controlling the motions of said tracks or wheels within the range defined by said connecting rods, as well as to support, at the same time, the excavator frame at the required height on the ground. Said corinecting rods are preferably fitted in pairs, in the shape of an articulated parallellograrn, with the related framesupporting and control means acting substantially along, or close to, a diagonal of same articulated parallelogram, to cause a widening or narrowing thereof, and thus a motion, to and from the stationary frame of excavator, of tracks and wheels connected therewith.

In connection with the above features, at least one suitable sleeve is preferably fitted on the excavator stationary frame, in Order to put the turntable at a higher level, whereby to prevent the boom from being hindered in its rotary motion, when the tracks or wheels rest on stepped planes. Means fitted to lower frame side are also provided to allow the excavator to rest directly on the ground, suchy means consisting of a platform, that is brought to rest on the ground in a pre-established widened position of said articulated parallelograms, and thus of widening of tread. Finally, the previously stated means for properly shifting the pivot points of booms and of related lifting cylinder(s) advantageously consist of at least one suitably shaped member, which supports said pivots, and that can be moved by driving mechanism, such member being in the shape of a substantially polygonal, and preferably triangular, plate, that is on turn pivotally supported by the stationary excavator frame, and is driven by a hydraulically or mechanically, or pneumatically or the like operated jack, having one end rigidly secured to the excavator frame, while its opposite end is pivotally connected with a point of said polygonal plate. Both pivot points of boom and of related cylinder(s) are advantageously located on said polygonal plate in such a manner that the former one be substantially at a level higher than the latter one, and located rearwardly thereof.

Brief description f the drawings FIG. 1 is a partial front view of an excavator according to the invention.

FIG. 2 is a cross sectional view, taken on theV line II--II of FIG. 1.

FIG. 3 is a side view of the excavator according to the invention, showing in particular the device adapted to shift the pivot points of the boom, and of related cylinder, by which the boom is driven.

FIG. 4 is a partial, diagrammatic section taken along the line IV--IV of FIG. 2, showing in particular the device by which the boom is inclined.

FIG. 5 is a partial front view of the excavator according to the invention, showing in particular the device by which the boom is inclined, and a practical application thereof.

FIG. 6 is a front view corresponding to that of FIG. 5, showing the device by which the excavator tread can be changed in a particular position of the excavator, and

FIG. 7 is a partial front view, showing a particular position of the excavator, while digging trenches.

Description of the preferred embodiments Referring to FIG. 1, the excavator 10 comprises a stationary frame 11, mounted on tracks 12 and 13 for its motion, and carrying on its top a turntable 14, revolvingly fitted on its vertical axis, and whereon the proper excavator is fitted. The excavator section consists of a boom 15, that is operated by the driving cylinder-piston aggregates 16 and 17 of the motor 18, and of the drivers cab 19, wherein the control levers 20, operated by the driver, are fitted. As described later, the stationary frame is connected with the tracks 12, 13 through pairs of connecting rods 21, 22 and 23, 24, by which articulated parallelograms are formed, and that are driven by the cylinderpiston sets 25, 26. Fitted on the same frame, is the stationary component 27 of a ball-joint linkage 28, that is controlled by the jacks 29, 30.

As better shown in FIG. 2, the frame 11 is supported by four pairs of connecting rods on each side thereof, and each set formed by two pairs of close-fitted connecting rods-ie., two articulated parallelograms-is driven by one of jacks 25, 26, while the ball-joint linkage 28 is preferably controlled by four jacks 29, 30, 31 and 32, respectively pivoted on the stationary frame, and on a central component 33, fastened to movable component of ball-joint linkage, being sarne jacks fitted with suitable cardan joints or the like, allowing also a side motion thereof.

Referring now to FIG. 3, it can be seen how-according to the inventionthe bucket boom 15 is not connected to the excavator body on a fixed pivot point, being conversely pivotally connected, along with the related driving cylinder-piston set 16, with a plate 35, that can be turned on its pivot point 36. Thus the boom 15 can be swiveled both on its own pivot point 37 and on the pivot point 36, while the related hydraulic cylinder 16 can also be swiveled on both pivot points 38 and 36, thereby obtaining a wider range of bucket motions, either vertically and horizontally, according to the positions taken by the plate 35, that can be moved by means of jack 40, which is connected on one end with a fixed pivot point on the excavator frame, and on the opposite end with the same pivot point 37 of boom 15. Such results are clearly shown in FIG. 3, where a and a' are the two positions which can be attained by the bucket, when the pivot point 37 of boom 15 is in its upper position 37', and consequently the pivot point 38 of driving cylinderpiston set is in its position 38', while b and b respectively are the positions that can be attained by the bucket, when the pivot points 37 and 38 are both in their lowest position, as shown in the drawing with solid lines, and finally c and c are the end positions that can be respectively attained in the longitudinal directions, when the pivot points are in their lifted and lowered positions.

As shown, by this arrangement the possibility is given to enlargeeven with small swiveling motions of plate 35-the working range of boom, while reaching at the same time a remarkable discharge height, and a noticeable digging depth, which features can be attained alternatively only with the conventional excavators having fixed pivot points. It is to be observed that, depending on the conditions under which the excavator will be set on work, the possibility is also given to conveniently adjust the position of fixed pivot point 36 on the frame, whereby a further, advantageous increase in either the discharge height, or in the digging depth can be obtained.

Referring now to the FIG. 4, the device by which the boom support can be laterally inclined in any direction is shown in full details therein. Such device, as already stated, consists of a ball-joint linkage, made up substantially of two components, i.e., a stationary component 27, consisting of two separable sections 41, 42, to allow the assembling of movable component 28, which is then retained in its position, in such a manner as to be able to turn in any direction round the point 43. To such a purpose, the fixed component 27 and the movable component 28 mutually contact on a spherical surface, obtained `by cutting a sphere along two planes parallel with each other, and with the equatorial plane, and extending on either sides of latter plane, being such planes respectively indicated by numerals 44 and 45 on the movable component, and by numerals 46 and 47 on the stationary component.

suitably combining two of such inclinations, a rotation of 1 the whole assembly on the center 43 is obtained as a final result, due to the principle of composition of movements. Two of such possible inclinations are clearly shown in FIG. 4, where d and d are the positions that can be attained by the base plate of upper `movable section of excavator. As it can be readily appreciated, by such a ball-joint linkage, the possibility is also given to attain a greater discharge height, anda larger. digging depth, according to the inclination of turntable 14, though the most convenient and advantageous; application of the abovedescribed device is that shown'in FIG. 5. In fact, in latter figure, the case is shown wherein the excavator is set to work on a slope, i.e., in the hills, and a 4 trench not perpendicular to ground, but having vertical walls is to be dug. In such a case, by acting on the jacks 29 and 30, the turntable 14 is inclined through the ball-joint linkages 27, 28, until the turntable-by which the boom and the drivers cab are supported-is perfectly horizontal, whereby the bucket can be set o-n work in the ground in an exactly vertical direction. It is to be observed that no need exists, to the above purpose, to have the excavator located as shown in the figure, i.e., with the tracks extending crosswise to the line of greatest slope, since it can be located in any other position whichmight appear the most convenient one. In order to keep the turntable 14 in an exactly horizontal position, a level indicator is fitted preferably in the drivers cab, whereby the required verticality of excavation can be controlled by the driver, in any position of the machine.

The device by which the excavator tread can be changed, and of which a brief mention has already been made in the description referred to FIG. l, is shown in FIG. 6. Such change is obtained by having the frame 11 connected with the tracks 12 and 13 by means of articulated parallelograms, consisting each of two pairs of connecting rods 21, 22 and 23, 24, respectively connected with the frame in the pivot points 51, 52 and 53, 54, and with the tracks in the pivot points 55, 56 and 5-7, 58. A pneumatically or otherwise driven jack is fitted along a diagonal of each articulated parallelogram, and is connected therewith, e.g. in the pivot points 51, 56 and 53, 58, thus allowing to extend or to restrict said parallelogram, whereby the related track is drawn away from, or brought closer to the frame. Therefore, not only the excavator tread can be changed at will, but also the distance between the frame axis and the axis of a single track can also be modified, when required by particular conditions. By the above system, in addition to the abovestated advantages, concerning the road transport of excavator, and the possibility to have very wide trenches dug, since the widening and restricting of tread respectively result in a lowering and lifting of frame, further advantages can be obtained, increasing both the depth of excavation and the height of discharge. Finally, the excavator frame 11 can be lowered until it comes to rest on the ground, thereby preventing all shocks and jerks, to which an excavator is usually submitted while operating, from being transmitted to not very rugged tracks and other drive mechanisms of the machine.

In FIG. 6, 12 and 13 are the positions of tracks at which the smallest tread is obtained, whereby the frame 11 is lifted at the most from the ground, being such positions coincident with those of FIG. 1.

A particular advantage of the abovedescribed arrangement is clearly shown in FIG. 7; the excavator illustrated therein is set to work on a trench 59, which banks 60, 61, while being parallel with each other, are however stepped down by a depth h. In such a case, the jacks 25 and 26 have been operated in such a manner as to close the parallelograms formed by the connecting rods 21 and 22 and to conveniently extend the parallelogram formed by the connecting rods; thus, both tracks are positioned at level with the ground and wholly adherent therewith, while Yon the other side the frame 11 is adjusted on a perfectly horizontal position, which can be controlled by an expressly provided level indicator, fitted in the drivers cab, which may be the Same instrument by which the movements of ball-joint linkage are controlled, or can ybe independent therefrom.

K It is to be remarked that, when particular requirements 'are to be met, as in the case of a very wide channel 59, the connecting rods can be replaced, on one or both sides 'of machine, with longer connecting rod, having a pin for the pivotal connection with the related jack, fitted in a suitable position, such as to prevent the need for the use of longer jacks. According to a particular embodiment from (not shown) use could be made of telescopically extendible rods, in order to conveniently increase the range of possible'tread changes, being in the latter case preferable to make telescopically extendible also the related jack. Finally, according to the invention, when works of the type as shown in FIG. 7 are to be carried out, a sleeve or the like can be possibly interposed 'between the frame 11 and the turntable 14 thus -bringing this latter at a higher level, in order to prevent the movable assembly from striking, while being rotated, a lifted track.

While the invention has been described in detail with respect to a certain, now preferred embodiment form thereof, it will be understood that various changes and modifications may be made therein, without departing from the scope of the invention as defined in the appended claims.

What I claim is:

1. An excavator comprising a chassis, a supporting frame on said chassis, an endless track adjustably secured at each of the sides of said frame, a body, an excavator boom supported by said body, a turntable for said body mounted for rotation about a substantially vertical axis, a 'tiltable component fixed to said turntable tiltably supported on said frame, link means connecting each endless track to a side of said frame, a first actuator means connected to said frame and tracks for individual positioning of said tracks relative to said frame, said tiltable component comprising a member having a first spherical zone between two parallel planes symmetrically spaced from the great circle of a sphere, a component fixed to said frame having a second spherical Zone concentric to and mating and frictionally engaged with said first spherical zone, whereby said tiltable component and said body and boom assembly supported thereby can be rotated in any direction about the common center of said spherical zones, and a second actuator means connected to said frame and to said tiltable component to control theswivel adjustment of said assembly relative to said frame.

2. An excavator as set forth in claim 1, wherein said link means comprise pairs of parallel links each having their ends pivotally connected to said frame and to one of said tracks to form articulated parallelograms and said first actuator means comprises jacks connected along diagonals of said parallelograms.

3. An excavator as set forth in claim 2, wherein said links extend nearly horizontally outwardly when said tracks are raised relative to said frame and extend downwardly when lowered for increasing the track gauge concurrently with the lowering of said frame relative to the ground.

4. An excavatoras set forth in claim 3 wherein said links are longer than the maximum clearance of said frame from the ground and said iirstactuator means can raise said tracks -to a height relative to said frame to cause said frame to rest on the ground.

5. An excavator for a self-propelled ground supported vehicle comprising a frame, a body andboom assembly mounted on said frame, means for tiltably and rotatably supporting said assembly on said frame and said means including a tiltable component comprising a member hav.- ing a rst spherical zone between two parallel planes symmetrically spaced from the great circle of a sphere, a component ixed to said frame having a second spherical zone concentric to and mating and frictionally engaged with said rst spherical zone, whereby said tiltable component and said body and boom assembly supported thereby can be rotated in any direction about the common center of said spherical zones, and an actuator means connected to said frame and to said tiltable component t0 control the swivel adjustment of said assembly relative to said frame.

6. An excavator as set forth in claim 5, wherein said component fixed to said frame comprises two elements symmetrically located at both sides of the plane com@ prising said great circle of the sphere.

7. A n excavator as set forth in claim 5, wherein said actuator means comprise a plurality of actuators acting upon said tiltable component in differing directions.

8. An excavator as set forth in claim 7 wherein a downwardly extending member xed to said tiltable component having an end portion spaced from the common center of said spherical zones extends at right angles to the plane comprising said great circle of said iirst spherical zone, and said actuators are evenly radially arranged about said end portion and are pivotally connected thereto.

References Cited UNITED STATES PATENTS -3,142,395 7/1964 Pingon 214-138 3,167,194 1/1965 Davis et al. 214-138 3,197,049 7/1965 Schwing 214-138 FOREIGN PATENTS 1,379,708 1,0/ 1964 France.

HUGO O. SCHULZ, Primary Examiner.

U.S. C1. X.R. 180-9.52, 41 

